The purpose of the activity is the assessment of thermal and dynamic response of a rubber torsional damper when subjected to continuous cycles of dynamic load related to use.
In particular it’s important to evaluate, for a given system of shaft speed, the dynamic response at different frequencies in terms of magnitude of angular displacement of the outer metal disk (on which the pulley is located) in function of the amplitude of displacement angle of internal disk (connected directly to the tree).
Each dynamic cycle also causes strain cycles on the rubber that dissipates thermal power for hysteresis causes. This value of power dissipation is a function of cycle frequencies examined, of the material and of the strain value that was reached in the cycle. After a transitional phase, the temperature of the rubber damper and metal disk inside and outside, settle down to a value, function of power dissipation, geometry considered and the speed of rotation (that govern the convective coefficient).
The properties of rubber are included in accordance with the tests on rubber Vamac. From the experimental curves it was possible to determine the shear modulus (G) and the value of damping (tan δ) versus frequency for a given value of reference temperature (T0). A temperature scaling law was found too, to take in account of the thermal variation of the material properties.
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